1. Field of the Invention
The present invention relates generally to compact optical channel performance monitors and spectrum analyzers.
2. Description of Background Art
Optical channel performance monitors (OCPMs) are of interest in a variety of telecommunication applications, such as wavelength divisional multiplexed (WDM) networks. The term “OCPM” is a comparatively new term commonly used to describe an optical monitoring apparatus capable of performing a variety of different measurement functions. OCPMs are versatile modules that may be used to emulate the function of a variety of test equipment, such as an optical channel monitor, optical performance monitor, optical power meter, or an optical spectrum analyzer. As one example, an OCPM system may be used to display the time-averaged power in individual wavelength channels, display an optical spectrum of one or more channels, display data for calculating the center wavelength of optical signals, or calculate the optical signal-to-noise ratio of individual channels.
An OCPM typically includes a grating to disperse input light into its component wavelengths. The light at a selected wavelength is detected by an optical detector. An OCPM typically includes its own signal processor to process data locally, although a host computer may perform additional data processing of raw data.
Typically, an OCPM system includes an OCPM and a local computer (e.g., a personal computer) to display data generated by the OCPM in a useful form. The local computer may also be used to provide control signals to the CPM.
One drawback of conventional OCPM systems is that they are larger and heavier than desired. A conventional OCPM system may not provide an optical spectrum analyzer function. The total size of the OCPM and its associated host computer occupies a significant amount of test-bench area. Additionally, the bulk a conventional OCPM makes it more difficult than desired to move the OCPM to a new location. Generally speaking, the size, weight, and other limitations of conventional OCPMs means that they cannot easily be used as field-test instruments.
Therefore, what is desired is a compact OCPM system.